Hello, my new house came with 5 adult chickens and eventhough I am new to this, it’s been going very well. 
 About a month ago, I added 4 pullets from D2D (great service) to the flock. However, I sectioned off part of the coop and the run for the new flock. About a week ago, I decided to start letting the two flock interact and things were going well until yesterday were I found one of the new pullets on the ground in the run with blood and a large opening behind the comb on the back of the neck. From what I found online, it seems that one or more the other chickens pecked at her. I tried to save her by cleaning the wound and applying some betadine, but she died shortly afterwards. 
 Now I am back to separating them. 
Is there anything I can do to help with the pecking? 
 please help if you experienced something similiar. 
 the experience was traumatizing. 

